Paço de Arcos is a locality situated in the municipality of Oeiras, Portugal. It was officially elevated to the status of a town by a decree issued on December 7, 1926. The area covers a total land area of 3.39 km².
In terms of local administration, the parish of Paço de Arcos merged into the new parish of Oeiras e São Julião da Barra, Paço de Arcos e Caxias in 2013. According to data from 2011, the locality had a population of 15,315 residents.